/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date:        15. February 2012
* $Revision: 	V1.1.0
*
* Project: 	    CMSIS DSP Library
* Title:	    arm_mat_scale_q31.c
*
* Description:	Multiplies a Q31 matrix by a scalar.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
*    Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
*    Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
*    Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
*    Documentation updated.
*
* Version 1.0.1 2010/10/05
*    Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
*    Production release and review comments incorporated.
*
* Version 0.0.5  2010/04/26
*    incorporated review comments and updated with latest CMSIS layer
*
* Version 0.0.3  2010/03/10
*    Initial version
* -------------------------------------------------------------------- */

#include "arm_math.h"

/**
 * @ingroup groupMatrix
 */

/**
 * @addtogroup MatrixScale
 * @{
 */

/**
 * @brief Q31 matrix scaling.
 * @param[in]       *pSrc points to input matrix
 * @param[in]       scaleFract fractional portion of the scale factor
 * @param[in]       shift number of bits to shift the result by
 * @param[out]      *pDst points to output matrix structure
 * @return     		The function returns either
 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
 *
 * @details
 * <b>Scaling and Overflow Behavior:</b>
 * \par
 * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.31 format.
 * These are multiplied to yield a 2.62 intermediate result and this is shifted with saturation to 1.31 format.
 */

arm_status arm_mat_scale_q31(
    const arm_matrix_instance_q31* pSrc,
    q31_t scaleFract,
    int32_t shift,
    arm_matrix_instance_q31* pDst)
{
	q31_t* pIn = pSrc->pData;                      /* input data matrix pointer */
	q31_t* pOut = pDst->pData;                     /* output data matrix pointer */
	uint32_t numSamples;                           /* total number of elements in the matrix */
	int32_t totShift = shift + 1;                  /* shift to apply after scaling */
	uint32_t blkCnt;                               /* loop counters  */
	arm_status status;                             /* status of matrix scaling      */
	q31_t in1, in2, out1;                          /* temporary variabels */

#ifndef ARM_MATH_CM0

	q31_t in3, in4, out2, out3, out4;              /* temporary variables */

#endif //      #ifndef ARM_MAT_CM0

#ifdef ARM_MATH_MATRIX_CHECK

	/* Check for matrix mismatch  */
	if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols)) {
		/* Set status as ARM_MATH_SIZE_MISMATCH */
		status = ARM_MATH_SIZE_MISMATCH;
	} else
#endif //    #ifdef ARM_MATH_MATRIX_CHECK
	{
		/* Total number of samples in the input matrix */
		numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;

#ifndef ARM_MATH_CM0

		/* Run the below code for Cortex-M4 and Cortex-M3 */

		/* Loop Unrolling */
		blkCnt = numSamples >> 2u;

		/* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
		 ** a second loop below computes the remaining 1 to 3 samples. */
		while(blkCnt > 0u) {
			/* C(m,n) = A(m,n) * k */
			/* Read values from input */
			in1 = *pIn;
			in2 = *(pIn + 1);
			in3 = *(pIn + 2);
			in4 = *(pIn + 3);

			/* multiply input with scaler value */
			in1 = ((q63_t) in1 * scaleFract) >> 32;
			in2 = ((q63_t) in2 * scaleFract) >> 32;
			in3 = ((q63_t) in3 * scaleFract) >> 32;
			in4 = ((q63_t) in4 * scaleFract) >> 32;

			/* apply shifting */
			out1 = in1 << totShift;
			out2 = in2 << totShift;

			/* saturate the results. */
			if(in1 != (out1 >> totShift))
				out1 = 0x7FFFFFFF ^ (in1 >> 31);

			if(in2 != (out2 >> totShift))
				out2 = 0x7FFFFFFF ^ (in2 >> 31);

			out3 = in3 << totShift;
			out4 = in4 << totShift;

			*pOut = out1;
			*(pOut + 1) = out2;

			if(in3 != (out3 >> totShift))
				out3 = 0x7FFFFFFF ^ (in3 >> 31);

			if(in4 != (out4 >> totShift))
				out4 = 0x7FFFFFFF ^ (in4 >> 31);


			*(pOut + 2) = out3;
			*(pOut + 3) = out4;

			/* update pointers to process next sampels */
			pIn += 4u;
			pOut += 4u;


			/* Decrement the numSamples loop counter */
			blkCnt--;
		}

		/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
		 ** No loop unrolling is used. */
		blkCnt = numSamples % 0x4u;

#else

		/* Run the below code for Cortex-M0 */

		/* Initialize blkCnt with number of samples */
		blkCnt = numSamples;

#endif /* #ifndef ARM_MATH_CM0 */

		while(blkCnt > 0u) {
			/* C(m,n) = A(m,n) * k */
			/* Scale, saturate and then store the results in the destination buffer. */
			in1 = *pIn++;

			in2 = ((q63_t) in1 * scaleFract) >> 32;

			out1 = in2 << totShift;

			if(in2 != (out1 >> totShift))
				out1 = 0x7FFFFFFF ^ (in2 >> 31);

			*pOut++ = out1;

			/* Decrement the numSamples loop counter */
			blkCnt--;
		}

		/* Set status as ARM_MATH_SUCCESS */
		status = ARM_MATH_SUCCESS;
	}

	/* Return to application */
	return (status);
}

/**
 * @} end of MatrixScale group
 */
